US4791418A - Signal light - Google Patents

Signal light Download PDF

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Publication number
US4791418A
US4791418A US07/065,849 US6584987A US4791418A US 4791418 A US4791418 A US 4791418A US 6584987 A US6584987 A US 6584987A US 4791418 A US4791418 A US 4791418A
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United States
Prior art keywords
light
liquid crystal
light source
signal light
signal
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US07/065,849
Inventor
Hideo Kawahara
Harunobu Yoshida
Masato Hyodo
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Raychem Corp
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Taliq Corp
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Priority claimed from JP61100191A external-priority patent/JPH0820570B2/en
Priority claimed from JP61170058A external-priority patent/JPS6325699A/en
Priority claimed from JP61170057A external-priority patent/JPS6326528A/en
Application filed by Taliq Corp filed Critical Taliq Corp
Assigned to TALIQ CORPORATION, 1277 REAMWOOD AVE., SUNNYVALE CA. A CORP. OF CA. reassignment TALIQ CORPORATION, 1277 REAMWOOD AVE., SUNNYVALE CA. A CORP. OF CA. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: HYODO, MASATO, KAWAHARA, HIDEO, YOSHIDA, HARUNOBU
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Assigned to RAYCHEM CORPORATION reassignment RAYCHEM CORPORATION ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: TALIQ CORPORATION
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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133602—Direct backlight
    • G02F1/133604—Direct backlight with lamps
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/13306—Circuit arrangements or driving methods for the control of single liquid crystal cells
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1334—Constructional arrangements; Manufacturing methods based on polymer dispersed liquid crystals, e.g. microencapsulated liquid crystals
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133621—Illuminating devices providing coloured light
    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F2201/00—Constructional arrangements not provided for in groups G02F1/00 - G02F7/00
    • G02F2201/36—Airflow channels, e.g. constructional arrangements facilitating the flow of air

Definitions

  • the present invention relates generally to signal lights, and more particularly to signal lights with increased visibility that are suitable for use as traffic signal lights, e.g., on roads or railways.
  • FIG. 1 A type of traffic signal light utilized heretofore is illustrated in FIG. 1.
  • Such lights generally comprise a lamp 10, a transparent colored cover 12, a casing 14, and a hood 16.
  • Signal lights with red and green, or red, yellow and green transparent colored plates 12 are utilized in combination, and traffic signals are given by lighting one or the other of the signal lights.
  • the present invention eliminates the above-mentioned drawback of signal lights, and provides a signal light which can easily be visually distinguished even under direct sunlight conditions.
  • An object of the present invention is to provide a signal light that produces a signal that is easily, visually distinguishable under direct sunlight conditions.
  • a further object of the present invention is to provide a signal light that protects the liquid crystal material from ultraviolet light.
  • Another object of the present invention is to provide a signal light that reduces glare otherwise present thereon.
  • the signal light disclosed herein is one which comprises a light source and a liquid crystal means disposed between the light source and a view area of the signal light for blocking or transmitting light according to a given electrical input.
  • the signal light further includes means for applying electrical input to the liquid crystal means to transmit light when the light source is energized and for removing the electrical input to block light when the light source is de-energized.
  • FIG. 1 is a schematic, longitudinal section of a conventional traffic signal light
  • FIG. 2 is a schematic, longitudinal section of a traffic signal light illustrating one aspect of the present invention
  • FIG. 3 is a schematic, longitudinal section of a traffic signal light illustrating another embodiment of the present invention.
  • FIG. 4 is a schematic, longitudinal section of a traffic signal light illustrating yet another embodiment of the present invention.
  • FIG. 2 shows a signal light 20 having a lamp 22 installed inside a casing 24.
  • a transparent colored plate or cover 26 is attached to the casing in front of the lamp.
  • a cylindrical hood 28 with a obliquely cut tip as shown at 27 is attached in front of the transparent colored plate 26.
  • An electro-optical liquid crystal device 30 is attached to the hood in a position which is removed from the colored plate by a distance of 5 centimeters or more.
  • the liquid crystal apparatus of device 30 may comprise an encapsulated operationally nematic liquid crystal material or nematic curvilinear line phases (NCAP) liquid crystal material.
  • NCAP nematic curvilinear line phases
  • the NCAP liquid crystal material scatters incident light.
  • incident light is transmitted through the NCAP material.
  • FIG. 2 A schematic representation of a circuit 32 for selectively applying or not an electric field to the liquid crystal material of device 30 and lamp 22 is illustrated in FIG. 2.
  • Such a circuit 32 may include an electric power supply 34, such as a battery, and a pair of linked switches 36 and 38.
  • the electric power supply may alternatively be a source of alternating current.
  • the circuit is connected by electrical leads 31,33 to electrodes 35,37 positioned on opposite sides or surfaces of the liquid crystal apparatus 30.
  • the liquid crystal material is located between the electrodes.
  • the electrodes 35,37 are subsantially optically transparent, and may be formed on optically transparent substrates 35a,37a such as an optically transparent polyester film.
  • the circuit may further include electrical leads 39,40 for supplying power from power supply 34 to lamp 22.
  • switch 38 when switch 36 is open switch 38 is also open and no electric field is applied to the liquid crystal material or to lamp 22. With switch 38 open, the liquid crystal material is in the so-called de-energized or field-off condition or mode wherein light is scattered and/or absorbed, especially when combined with an appropriate dye, by the liquid crystal material.
  • switch 38 When switch 36 is closed switch 38 is also closed, and power is supplied to lamp 22 and an electric field is applied across the liquid crystal material of device 30. Device 30 is then in the so-called energized or field-on condition or mode wherein light is transmitted through the liquid crystal material.
  • the signal light portion that is lit is more easily visually distinguished from the signal light portion that is not lit.
  • the visual distinguishability of the transparent colored plate 26 may be increased by coating the surface of that plate with a transparent light-scattering paint so that the light passing through the paint is scattered.
  • scattering is more effective if the surface coated with the paint is surface 26a that faces light source 22. This embodiment provides enhanced light scattering in the field-off state.
  • the visual distinguishability of the transparent colored plate 26 may be increased by installing a light-transmitting body 44 coated with a transparent light-reflecting film, which absorbs little light, such as a thin plate of TiO 2 or ZrO 2 , between the transparent colored plate and lamp 22.
  • a coating of such a material may be formed on the interior surface 26a of the transparent colored plate so that light reflected by a sunlight reflecting body is passed through under direct sunlight.
  • FIG. 3 illustrates another embodiment of the present invention wherein liquid crystal apparatus 30 is in an inclined position so that it is oriented perpendicular to a line of sight 46 with respect to an observer 42.
  • Inclining liquid crystal device 30 with respect to light source 22, helps to eliminate glare that might otherwise be perceived by observer 42. As a result, interference with the recognition of the signal light due to reflection from surfaces of the transparent electrode substrates of the liquid crystal device, for example, is minimized.
  • This embodiment may further include a film 48 for absorbing ultraviolet light to prevent the deterioration of the liquid crystal material that might otherwise occur in direct sunlight.
  • the film may be applied to the outer surface of the liquid crystal device 30, e.g., it may be applied directly to the side of substrate 37a opposite from electrode 37.
  • the film may be formed by mixing an ultraviolet light absorbing compound such as a benzophenone derivative, a salicylic acid derivative, or benzotriazole with a resin such as a polymethyl methacrylate, polyethylene, polyethylene terephthalte, or polyvinylchloride.
  • the embodiment illustrated in FIG. 3 may also include openings 50, e.g., circular holes or louver-type openings, in the outer cylinder 28'.
  • openings 50 e.g., circular holes or louver-type openings
  • the temperature in the outer cylinder and thus in the liquid crystal device 30 may be large enough to detrimentally effect performance of the liquid crystal material.
  • heat-releasing openings 50 in the outer cylinder the temperature rise of the liquid crystal material is diminished, so that deterioration of its performance characteristics due to high temperature is avoided.
  • FIG. 4 Yet another embodiment of the present invention is illustrated in FIG. 4. As shown, this embodiment includes a layer of non-reflecting light film 52 applied to the side of substrate 37a opposite electrode 37.
  • Layer 52 e.g., may comprise a relatively thin layer of silicon dioxide.
  • Layer 52 reduces the reflection of light striking liquid cyrstal device 30 from the direction of observer 42.
  • layer 52 minimizes glare or the disturbing effect of such light on persons viewing the signal light. As a result, the visual distinguishability of the color of transparent colored plate 26 is enhanced.
  • the layer 52 of silicon dioxide may be formed by causing the outer surface of substrate 37a to contact a more or less saturated hydrofluorosilicic acid solution of silicon dioxide for a prescribed period of time.
  • the amount of reflection from the front surface of the signal light may also be reduced by coating the surfaces of one or the other of the transparent electrodes 35,37 with such a non-reflecting film.
  • the present invention may utilize a liquid crystal device having a polarizer and analyzer with a liquid crystal oriented between transparent electrodes so that the liquid crystal has a twisted nematic effect
  • the present invention is not limited to use with traffic signals. It may utilized as a signal or warning lamp in various types of equipment and instruments. In such cases, the transparent colored plate be eliminated.

Abstract

A signal light comprising a light source and a liquid crystal means. The liquid crystal means is disposed between the light source and a viewing area of the signal light for blocking and transmitting light according to a given electrical input. The signal light further includes means for energizing the light source when the liquid crystal means transmits light and for de-energizing the light source when the liquid crystal means blocks light.

Description

BACKGROUND OF THE INVENTION
The present invention relates generally to signal lights, and more particularly to signal lights with increased visibility that are suitable for use as traffic signal lights, e.g., on roads or railways.
A type of traffic signal light utilized heretofore is illustrated in FIG. 1. Such lights generally comprise a lamp 10, a transparent colored cover 12, a casing 14, and a hood 16. Signal lights with red and green, or red, yellow and green transparent colored plates 12 are utilized in combination, and traffic signals are given by lighting one or the other of the signal lights.
However, when direct sunlight strikes a traffic signal light, an extinguished signal light is difficult to distinguish from a lit signal light. As a result, there is a danger of accident due to misreading of the signals.
It is possible to increase the brightness of lamp 10 in order to improve the visual distinguishability of the signal light. However there are limits to the effectiveness of this technique under direct sunlight.
The present invention eliminates the above-mentioned drawback of signal lights, and provides a signal light which can easily be visually distinguished even under direct sunlight conditions.
An object of the present invention is to provide a signal light that produces a signal that is easily, visually distinguishable under direct sunlight conditions.
A further object of the present invention is to provide a signal light that protects the liquid crystal material from ultraviolet light.
Another object of the present invention is to provide a signal light that reduces glare otherwise present thereon.
SUMMARY OF THE INVENTION
As may be seen hereinafter, the signal light disclosed herein is one which comprises a light source and a liquid crystal means disposed between the light source and a view area of the signal light for blocking or transmitting light according to a given electrical input. The signal light further includes means for applying electrical input to the liquid crystal means to transmit light when the light source is energized and for removing the electrical input to block light when the light source is de-energized.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be described in more detail hereinafter in conjunction with the drawings wherein:
FIG. 1 is a schematic, longitudinal section of a conventional traffic signal light;
FIG. 2 is a schematic, longitudinal section of a traffic signal light illustrating one aspect of the present invention;
FIG. 3 is a schematic, longitudinal section of a traffic signal light illustrating another embodiment of the present invention; and
FIG. 4 is a schematic, longitudinal section of a traffic signal light illustrating yet another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, wherein like reference numerals for like components are utilized through the drawings, attention is first directed to FIG. 2. FIG. 2 shows a signal light 20 having a lamp 22 installed inside a casing 24. A transparent colored plate or cover 26 is attached to the casing in front of the lamp. A cylindrical hood 28 with a obliquely cut tip as shown at 27 is attached in front of the transparent colored plate 26. An electro-optical liquid crystal device 30 is attached to the hood in a position which is removed from the colored plate by a distance of 5 centimeters or more.
The liquid crystal apparatus of device 30 may comprise an encapsulated operationally nematic liquid crystal material or nematic curvilinear line phases (NCAP) liquid crystal material. A detailed explanation of operationally nematic or NCAP liquid crystal material is provided in U.S. Pat. No. 4,616,903 issued Oct. 14, 1986, in the name of Fergason, entitled ENCAPSULATED LIQUID CRYSTAL AND METHOD, assigned to Manchester R&D Partnership, the disclosure of which is hereby incorporated by reference. Reference may also be made to U.S. Pat. No. 4,435,047, issued Mar. 6, 1984 in the name of Fergason, entitled ENCAPSULATED LIQUID CRYSTAL AND METHOD, assigned to Manchester R&D Partnership, which disclosure is also hereby incorporated by reference.
In the field-off condition, or in any other condition which results in the liquid crystal being in a distorted or randomly aligned state, the NCAP liquid crystal material scatters incident light. In the field-on condition or aligned state, incident light is transmitted through the NCAP material.
A schematic representation of a circuit 32 for selectively applying or not an electric field to the liquid crystal material of device 30 and lamp 22 is illustrated in FIG. 2.
Such a circuit 32 may include an electric power supply 34, such as a battery, and a pair of linked switches 36 and 38. The electric power supply may alternatively be a source of alternating current. The circuit is connected by electrical leads 31,33 to electrodes 35,37 positioned on opposite sides or surfaces of the liquid crystal apparatus 30. The liquid crystal material is located between the electrodes.
The electrodes 35,37 are subsantially optically transparent, and may be formed on optically transparent substrates 35a,37a such as an optically transparent polyester film.
The circuit may further include electrical leads 39,40 for supplying power from power supply 34 to lamp 22. Operationally, when switch 36 is open switch 38 is also open and no electric field is applied to the liquid crystal material or to lamp 22. With switch 38 open, the liquid crystal material is in the so-called de-energized or field-off condition or mode wherein light is scattered and/or absorbed, especially when combined with an appropriate dye, by the liquid crystal material.
When switch 36 is closed switch 38 is also closed, and power is supplied to lamp 22 and an electric field is applied across the liquid crystal material of device 30. Device 30 is then in the so-called energized or field-on condition or mode wherein light is transmitted through the liquid crystal material.
When the lamp is off or de-energized and the liquid crystal material is in the field-off or non-aligned or relatively free state, i.e., incident light is scattered and/or absorbed, neither lamp 22 nor transparent cover 26 can be visually observed by an observer or observing instrument 42 in the viewing area 43 in front of the signal. On the other hand, when the lamp is lit or energized and the liquid crystal material is in the so-called field-on or energized or aligned state, light is transmitted through the liquid crystal apparatus 30 without being scattered. Accordingly, light from the lamp passes through the transparent colored plate 26 and can be readily visually observed by observer 42.
As a result, the signal light portion that is lit is more easily visually distinguished from the signal light portion that is not lit.
In the signal light of the present invention, the visual distinguishability of the transparent colored plate 26 may be increased by coating the surface of that plate with a transparent light-scattering paint so that the light passing through the paint is scattered. In this embodiment, scattering is more effective if the surface coated with the paint is surface 26a that faces light source 22. This embodiment provides enhanced light scattering in the field-off state.
Furthermore, the visual distinguishability of the transparent colored plate 26 may be increased by installing a light-transmitting body 44 coated with a transparent light-reflecting film, which absorbs little light, such as a thin plate of TiO2 or ZrO2, between the transparent colored plate and lamp 22. Alternatively, a coating of such a material may be formed on the interior surface 26a of the transparent colored plate so that light reflected by a sunlight reflecting body is passed through under direct sunlight.
FIG. 3 illustrates another embodiment of the present invention wherein liquid crystal apparatus 30 is in an inclined position so that it is oriented perpendicular to a line of sight 46 with respect to an observer 42. Inclining liquid crystal device 30 with respect to light source 22, helps to eliminate glare that might otherwise be perceived by observer 42. As a result, interference with the recognition of the signal light due to reflection from surfaces of the transparent electrode substrates of the liquid crystal device, for example, is minimized.
This embodiment may further include a film 48 for absorbing ultraviolet light to prevent the deterioration of the liquid crystal material that might otherwise occur in direct sunlight. The film may be applied to the outer surface of the liquid crystal device 30, e.g., it may be applied directly to the side of substrate 37a opposite from electrode 37. The film may be formed by mixing an ultraviolet light absorbing compound such as a benzophenone derivative, a salicylic acid derivative, or benzotriazole with a resin such as a polymethyl methacrylate, polyethylene, polyethylene terephthalte, or polyvinylchloride.
The embodiment illustrated in FIG. 3 may also include openings 50, e.g., circular holes or louver-type openings, in the outer cylinder 28'. In the case of a signal light which is in continuance use, such as a push button light, the temperature in the outer cylinder and thus in the liquid crystal device 30 may be large enough to detrimentally effect performance of the liquid crystal material. By forming heat-releasing openings 50 in the outer cylinder, the temperature rise of the liquid crystal material is diminished, so that deterioration of its performance characteristics due to high temperature is avoided.
Yet another embodiment of the present invention is illustrated in FIG. 4. As shown, this embodiment includes a layer of non-reflecting light film 52 applied to the side of substrate 37a opposite electrode 37. Layer 52, e.g., may comprise a relatively thin layer of silicon dioxide. Layer 52 reduces the reflection of light striking liquid cyrstal device 30 from the direction of observer 42. Thus, layer 52 minimizes glare or the disturbing effect of such light on persons viewing the signal light. As a result, the visual distinguishability of the color of transparent colored plate 26 is enhanced.
The layer 52 of silicon dioxide may be formed by causing the outer surface of substrate 37a to contact a more or less saturated hydrofluorosilicic acid solution of silicon dioxide for a prescribed period of time. The amount of reflection from the front surface of the signal light may also be reduced by coating the surfaces of one or the other of the transparent electrodes 35,37 with such a non-reflecting film.
Instead of the NCAP liquid cyrstal material, the present invention may utilize a liquid crystal device having a polarizer and analyzer with a liquid crystal oriented between transparent electrodes so that the liquid crystal has a twisted nematic effect
The present invention is not limited to use with traffic signals. It may utilized as a signal or warning lamp in various types of equipment and instruments. In such cases, the transparent colored plate be eliminated.
Although certain specific embodiments of the invention have been described herein in detail, the invention is not to be limited only to such embodiments, but rather only by the appended claims.

Claims (20)

What is claimed is:
1. A signal light comprising
a light source disposed in the casing for the signal light;
a liquid crystal means disposed between said light source and a viewing area of the signal light for blocking or transmitting light according to a given electrical input;
means for applying said electrical input to said liquid cyrstal means to transmit light when said light source is energized and for removing said electrical input to block light when said light source is de-energized; and
a substantially transparent colored plate disposed between said light source and said liquid crystal means so that light from said light source may be transmitted therethrough when said light source is energized, the surface of said transparent colored plate coated with a transparent light-scattering paint.
2. The signal light of claim 1 wherein said surface is on the side of said transparent colored plate that faces said light source.
3. The signal light of claim 1 further including a light transparent layer having a light-reflecting film disposed between said liquid crystal means and said light source.
4. The signal of claim 1 in which said liquid crystal means is inclined from the vertical with respect to said light source so that the front surface of said liquid cyrstal means is oriented substantially perpendicular to a line of sight of an observer in the view area of the signal light.
5. The signal light of claim 1 further including a layer of material disposed on the side of said liquid crystal means opposite from said light source for absorbing ultraviolet light impinging thereon.
6. The signal light of claim 5 in which said liquid cystal means is inclined from the vertical with respect to said light source so that the front surface of said liquid crystal means is oriented substantially perpendicular to a line of sight of an observer in the viewing area of the signal light.
7. The signal light of claims 1, 5 or 6 further including an outer cylindrical hood extending from said casing and said liquid crystal means disposed within said hood in front of said light source and openings formed in said hood between said liquid crystal means and said light source for releasing heat therefrom.
8. The signal light of claim 1 further including a layer of material disposed on the side of said liquid crystal means opposite from said light source for reducing the reflection of light therefrom.
9. The signal light of claim 8 in which said liquid crystal means is inclined from the vertical with respect to said light source so that the front surface of said liquid crystal means is oriented substantially perpendicular to a line of sight of an observer in the viewing area of the signal light.
10. The signal light of claims 8 or 9 further including an outer cylindrical hood extending from said casing and said liquid crystal means disposed within said hood in front of said light source and openings formed in said hood between said liquid crystal means and said light source for releasing heat therefrom.
11. The signal light of claims 1, 5 or 8 wherein said liquid crystal means comprises a liquid crystal material having a twisted nematic effect.
12. The signal light of claims 1, 5 or 8 wherein said liquid crystal means comprises a liquid crystal material and a containment means for inducing a distorted alignment of said liquid crystal material which in response to such alignment at least one of scatters and absorbs light and which in response to said electrical input reduces the amount of such scattering or absorption.
13. The signal light of claim 12 in which said liquid crystal is birefringent and has an ordinary index of refraction in the presence of an electric field that is substantially matched to the index of refraction of said containment means to minimize refraction and scattering of light and an extraordinary index of refraction in the absence of said electric field that is different from the index of refraction of said containment means to cause refraction and scattering of light.
14. The signal light of claim 12 further comprising electrode means at the opposite surfaces of said liquid crystal material and containment means for applying said electrical input to said liquid crystal material.
15. The signal light of claim 14 further including circuit means for providing electric energy to said light source and said electrode means to effect application of said electrical input to said light source and said liquid crystal means.
16. The signal light of claim 14 further comprising substrate means for supporting the combination of said liquid crystal material and said containment means.
17. The signal light of claim 16 wherein said electrode means are supported on said substrate means.
18. A signal light comprising:
a light source disposed toward the rear of a casing for the signal light;
a liquid crystal means disposed between said light source and a viewing area of the signal light for blocking or transmitting light according to a given electrical input;
means for applying said electrical input to said liquid crystal means to transmit light when said light source is energized and for removing said electrical input to block light when said light source is de-energized;
a substantially transparent colored plate disposed between said light source and said liquid crystal means so that light from said light source may be transmitted therethrough when said light source is energized; and
an outer cylindrical hood extending from said casing with said liquid crystal means disposed within said hood in front of said light source and openings formed in said hood between said liquid crystal means and said light source for releasing heat therefrom.
19. A signal light comprising:
a light source in a casing for the signal light;
a liquid crystal means disposed between said light source and a viewing area of the signal light for blocking or transmitting light according to a given electrical input, said liquid crytal means inclined from the vertical so that the front surface of said liquid crystal means is oriented substantially perpendicular to a line of sight of an observer in the viewing area of the signal light;
means for applying said electrical input to said liquid crystal means to transmit light when said light source is energized and for removing said electrical input to block light when said light source is de-energized; and
a substantially transparent colored plate disposed between said light source and said liquid crystal means so that light from said light source may be transmitted therethrough when said light source is energized.
20. The signal light of claim 19 further including an outer cylindrical hood extending from said casing wherein said liquid crystal means is disposed within said hood in front of said light source and openings are formed in said hood between said liquid crystal means and said light source for releasing heat therefrom.
US07/065,849 1986-04-30 1987-06-24 Signal light Expired - Lifetime US4791418A (en)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
JP61100191A JPH0820570B2 (en) 1986-04-30 1986-04-30 Optical fiber cable wiring structure
JP61170058A JPS6325699A (en) 1986-07-18 1986-07-18 Formant extractor
JP61170057A JPS6326528A (en) 1986-07-18 1986-07-18 Manufacture of angular velocity sensor

Publications (1)

Publication Number Publication Date
US4791418A true US4791418A (en) 1988-12-13

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Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4958915A (en) * 1985-07-12 1990-09-25 Canon Kabushiki Kaisha Liquid crystal apparatus having light quantity of the backlight in synchronism with writing signals
EP0495616A2 (en) * 1991-01-15 1992-07-22 Illinois Tool Works Inc. Readable display stucture
US5139578A (en) * 1991-01-22 1992-08-18 Valley Charles R Liquid crystal coverslides for solar cells
US5153760A (en) * 1990-06-13 1992-10-06 Ahmed Adel A A Oscillating photovoltaic optical shutter for reflective display
EP0526838A1 (en) * 1991-07-29 1993-02-10 Eaton Corporation High reliability, low intensity back lit SR and NVGC indicator assembly
WO1993009524A1 (en) * 1991-11-05 1993-05-13 Magnascreen Corporation Liquid crystal lens assembly
US5327154A (en) * 1987-10-26 1994-07-05 Yazaki Corporation Indication display unit for vehicles
US5539545A (en) * 1993-05-18 1996-07-23 Semiconductor Energy Laboratory Co., Ltd. Method of making LCD in which resin columns are cured and the liquid crystal is reoriented
US5546208A (en) * 1993-02-19 1996-08-13 Semiconductor Energy Laboratory Co., Ltd. Electrooptical device involving a mixture of liquid crystal, photo curable resins and reaction initiating material for forming resinous columns
US5631665A (en) * 1992-11-13 1997-05-20 Nippon Hoso Kyokai Liquid crystal device, driving method thereof, liquid crystal apparatus, and illumination apparatus
US5676456A (en) * 1995-12-22 1997-10-14 Ncr Corporation Indicator device
US5739882A (en) * 1991-11-18 1998-04-14 Semiconductor Energy Laboratory Co., Ltd. LCD polymerized column spacer formed on a modified substrate, from an acrylic resin, on a surface having hydrophilic and hydrophobic portions, or at regular spacings
US5764316A (en) * 1992-01-30 1998-06-09 Nippon Hoso Kyokai Liquid crystal dimmer plate and lighting system including the same
US20030193470A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
DE102013207416A1 (en) * 2013-04-24 2014-10-30 Siemens Aktiengesellschaft light signal
US8888304B2 (en) 2012-05-10 2014-11-18 Christopher V. Beckman Optical control techniques
US20180009453A1 (en) * 2015-01-12 2018-01-11 Siemens Aktiengesellschaft Light Signal
US11384921B1 (en) * 2021-07-21 2022-07-12 Christopher Neal Bichon Snow shield assembly for use with a traffic signal

Citations (39)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1127223A (en) * 1913-04-19 1915-02-02 William C Fogle Display-cabinet.
US1359492A (en) * 1920-07-01 1920-11-23 Michael J Demuth Sign-holder
US1888564A (en) * 1930-02-01 1932-11-22 Card Display Inc Display device
US2871599A (en) * 1954-04-07 1959-02-03 Walter J Kolb Traffic signal adaptor unit
US3245075A (en) * 1964-02-24 1966-04-05 Henry N Staats Traffic signal light shroud
US3377479A (en) * 1963-10-18 1968-04-09 Sendlinger Optische Glaswerke Signal searchlight with end plate carrying optical directional means and with diaphragms arranged in the inner path of rays to eliminate phantom light caused by inner reflection
US3499112A (en) * 1967-03-31 1970-03-03 Rca Corp Electro-optical device
US3853392A (en) * 1973-09-13 1974-12-10 Hoffmann La Roche Gasket for liquid crystal light shutters
US3905682A (en) * 1974-06-14 1975-09-16 Rca Corp Liquid crystal devices of improved contrast
US3992082A (en) * 1974-01-29 1976-11-16 Siemens Aktiengesellschaft Compound liquid crystal indicator screen
US4003149A (en) * 1974-11-26 1977-01-18 Vries Peter De Display device and display unit for use therein
US4268126A (en) * 1978-12-20 1981-05-19 Allied Chemical Corporation Thermal-pane window with liquid crystal shade
US4289383A (en) * 1979-09-04 1981-09-15 Timex Corporation Lighted dot matrix display
US4315258A (en) * 1980-02-15 1982-02-09 The United States Of America As Represented By The Secretary Of The Navy Transmissive and reflective liquid crystal display
US4386836A (en) * 1979-12-28 1983-06-07 Kabushiki Kaisha Suwa Seikosha Electro-photographic printer
US4398805A (en) * 1981-07-06 1983-08-16 General Electric Company Transflective liquid crystal display
US4408836A (en) * 1980-02-28 1983-10-11 Sharp Kabushiki Kaisha Wide screen LCD panel with electrical terminal connections
US4422726A (en) * 1981-10-14 1983-12-27 Eaton Corporation Method of making an electro-optical display
US4435047A (en) * 1981-09-16 1984-03-06 Manchester R & D Partnership Encapsulated liquid crystal and method
JPS5981624A (en) * 1982-11-01 1984-05-11 Stanley Electric Co Ltd Liquid crystal cell and its manufacture
US4456335A (en) * 1978-12-20 1984-06-26 Allied Corporation Thermal-pane window with liquid crystal shade
US4457589A (en) * 1981-02-16 1984-07-03 Canon Kabushiki Kaisha Electro-optic device with particular location of electrode cross-overs
US4488772A (en) * 1982-09-02 1984-12-18 Gte Automatic Electric Inc. Electro-optic indicating device
US4514920A (en) * 1982-11-16 1985-05-07 Doron Shafrir Display module
US4556289A (en) * 1983-03-21 1985-12-03 Manchester R & D Partnership Low birefringence encapsulated liquid crystal and optical shutter using same
US4562433A (en) * 1980-09-02 1985-12-31 Mcdonnell Douglas Corporation Fail transparent LCD display
US4579423A (en) * 1981-09-16 1986-04-01 Manchester R & D Partnership Encapsulated liquid crystal and method
US4580876A (en) * 1983-11-02 1986-04-08 Michael Stolov Substratum for liquid crystal displays
US4584786A (en) * 1982-12-23 1986-04-29 Gte Automatic Electric Inc. Information panel assembly
US4591233A (en) * 1983-03-21 1986-05-27 Manchester R & D Partnership Enhanced scattering in voltage sensitive encapsulated liquid crystal with spaced apart absorber
US4596445A (en) * 1983-03-30 1986-06-24 Manchester R & D Partnership Colored encapsulated liquid crystal apparatus using enhanced scattering
US4603945A (en) * 1984-03-02 1986-08-05 Manchester R & D Partnership Liquid crystal graphics imager and method
US4605284A (en) * 1981-09-16 1986-08-12 Manchester R & D Partnership Encapsulated liquid crystal and method
US4606611A (en) * 1981-09-16 1986-08-19 Manchester R & D Partnership Enhanced scattering in voltage sensitive encapsulated liquid crystal
US4613207A (en) * 1984-05-08 1986-09-23 Manchester R & D Partnership Liquid crystal projector and method
US4643528A (en) * 1985-03-18 1987-02-17 Manchester R & D Partnership Encapsulated liquid crystal and filler material
US4652851A (en) * 1983-11-07 1987-03-24 Ian Lewin Lamp control system
US4662720A (en) * 1983-03-30 1987-05-05 Manchester R & D Partnership Colored encapsulated liquid crystal devices using imbibition of colored dyes and scanned multicolor displays
US4693557A (en) * 1984-03-02 1987-09-15 Manchester R & D Partnership Liquid crystal motion picture projector

Patent Citations (40)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1127223A (en) * 1913-04-19 1915-02-02 William C Fogle Display-cabinet.
US1359492A (en) * 1920-07-01 1920-11-23 Michael J Demuth Sign-holder
US1888564A (en) * 1930-02-01 1932-11-22 Card Display Inc Display device
US2871599A (en) * 1954-04-07 1959-02-03 Walter J Kolb Traffic signal adaptor unit
US3377479A (en) * 1963-10-18 1968-04-09 Sendlinger Optische Glaswerke Signal searchlight with end plate carrying optical directional means and with diaphragms arranged in the inner path of rays to eliminate phantom light caused by inner reflection
US3245075A (en) * 1964-02-24 1966-04-05 Henry N Staats Traffic signal light shroud
US3499112A (en) * 1967-03-31 1970-03-03 Rca Corp Electro-optical device
US3853392A (en) * 1973-09-13 1974-12-10 Hoffmann La Roche Gasket for liquid crystal light shutters
US3992082A (en) * 1974-01-29 1976-11-16 Siemens Aktiengesellschaft Compound liquid crystal indicator screen
US3905682A (en) * 1974-06-14 1975-09-16 Rca Corp Liquid crystal devices of improved contrast
US4003149A (en) * 1974-11-26 1977-01-18 Vries Peter De Display device and display unit for use therein
US4456335A (en) * 1978-12-20 1984-06-26 Allied Corporation Thermal-pane window with liquid crystal shade
US4268126A (en) * 1978-12-20 1981-05-19 Allied Chemical Corporation Thermal-pane window with liquid crystal shade
US4289383A (en) * 1979-09-04 1981-09-15 Timex Corporation Lighted dot matrix display
US4386836A (en) * 1979-12-28 1983-06-07 Kabushiki Kaisha Suwa Seikosha Electro-photographic printer
US4315258A (en) * 1980-02-15 1982-02-09 The United States Of America As Represented By The Secretary Of The Navy Transmissive and reflective liquid crystal display
US4408836A (en) * 1980-02-28 1983-10-11 Sharp Kabushiki Kaisha Wide screen LCD panel with electrical terminal connections
US4562433A (en) * 1980-09-02 1985-12-31 Mcdonnell Douglas Corporation Fail transparent LCD display
US4457589A (en) * 1981-02-16 1984-07-03 Canon Kabushiki Kaisha Electro-optic device with particular location of electrode cross-overs
US4398805A (en) * 1981-07-06 1983-08-16 General Electric Company Transflective liquid crystal display
US4606611A (en) * 1981-09-16 1986-08-19 Manchester R & D Partnership Enhanced scattering in voltage sensitive encapsulated liquid crystal
US4435047A (en) * 1981-09-16 1984-03-06 Manchester R & D Partnership Encapsulated liquid crystal and method
US4616903A (en) * 1981-09-16 1986-10-14 Manchester R & D Partnership Encapsulated liquid crystal and method
US4605284A (en) * 1981-09-16 1986-08-12 Manchester R & D Partnership Encapsulated liquid crystal and method
US4579423A (en) * 1981-09-16 1986-04-01 Manchester R & D Partnership Encapsulated liquid crystal and method
US4422726A (en) * 1981-10-14 1983-12-27 Eaton Corporation Method of making an electro-optical display
US4488772A (en) * 1982-09-02 1984-12-18 Gte Automatic Electric Inc. Electro-optic indicating device
JPS5981624A (en) * 1982-11-01 1984-05-11 Stanley Electric Co Ltd Liquid crystal cell and its manufacture
US4514920A (en) * 1982-11-16 1985-05-07 Doron Shafrir Display module
US4584786A (en) * 1982-12-23 1986-04-29 Gte Automatic Electric Inc. Information panel assembly
US4591233A (en) * 1983-03-21 1986-05-27 Manchester R & D Partnership Enhanced scattering in voltage sensitive encapsulated liquid crystal with spaced apart absorber
US4556289A (en) * 1983-03-21 1985-12-03 Manchester R & D Partnership Low birefringence encapsulated liquid crystal and optical shutter using same
US4596445A (en) * 1983-03-30 1986-06-24 Manchester R & D Partnership Colored encapsulated liquid crystal apparatus using enhanced scattering
US4662720A (en) * 1983-03-30 1987-05-05 Manchester R & D Partnership Colored encapsulated liquid crystal devices using imbibition of colored dyes and scanned multicolor displays
US4580876A (en) * 1983-11-02 1986-04-08 Michael Stolov Substratum for liquid crystal displays
US4652851A (en) * 1983-11-07 1987-03-24 Ian Lewin Lamp control system
US4603945A (en) * 1984-03-02 1986-08-05 Manchester R & D Partnership Liquid crystal graphics imager and method
US4693557A (en) * 1984-03-02 1987-09-15 Manchester R & D Partnership Liquid crystal motion picture projector
US4613207A (en) * 1984-05-08 1986-09-23 Manchester R & D Partnership Liquid crystal projector and method
US4643528A (en) * 1985-03-18 1987-02-17 Manchester R & D Partnership Encapsulated liquid crystal and filler material

Cited By (37)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4958915A (en) * 1985-07-12 1990-09-25 Canon Kabushiki Kaisha Liquid crystal apparatus having light quantity of the backlight in synchronism with writing signals
US5327154A (en) * 1987-10-26 1994-07-05 Yazaki Corporation Indication display unit for vehicles
US7006181B2 (en) 1990-03-23 2006-02-28 Matsushita Electric Industrial Co., Ltd. Data processing apparatus
US6990595B2 (en) 1990-03-23 2006-01-24 Matsushita Electric Industrial Co., Ltd. Data processing apparatus
US20030197818A1 (en) * 1990-03-23 2003-10-23 Mitsuaki Oshima Data processing apparatus
US20030193633A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US20030193634A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US20030193466A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US7821489B2 (en) 1990-03-23 2010-10-26 Panasonic Corporation Data processing apparatus
US7120809B2 (en) 1990-03-23 2006-10-10 Matsushita Electric Industrial Co., Ltd. Data processing apparatus
US7079108B2 (en) 1990-03-23 2006-07-18 Matsushita Electric Industrial Co., Ltd. Data processing apparatus
US7024572B2 (en) 1990-03-23 2006-04-04 Matsushita Electric Industrial Co., Ltd. Data processing apparatus
US20030193467A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US6882389B2 (en) 1990-03-23 2005-04-19 Matsushita Electric Industrial Co., Ltd. Transflective LCD device with different transmission parts each having a particular transmittance
US6952248B2 (en) 1990-03-23 2005-10-04 Matsushita Electric Industrial Co., Ltd. Data processing apparatus
US20030193470A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US20030193468A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US20030193469A1 (en) * 1990-03-23 2003-10-16 Mitsuaki Oshima Data processing apparatus
US6909483B2 (en) 1990-03-23 2005-06-21 Matsushita Electric Industrial Co., Ltd. Transflective LCD device with different transmission parts each having a particular transmittance
US5153760A (en) * 1990-06-13 1992-10-06 Ahmed Adel A A Oscillating photovoltaic optical shutter for reflective display
EP0495616A2 (en) * 1991-01-15 1992-07-22 Illinois Tool Works Inc. Readable display stucture
EP0495616A3 (en) * 1991-01-15 1993-02-03 Illinois Tool Works, Inc. Readable display stucture
US5139578A (en) * 1991-01-22 1992-08-18 Valley Charles R Liquid crystal coverslides for solar cells
EP0526838A1 (en) * 1991-07-29 1993-02-10 Eaton Corporation High reliability, low intensity back lit SR and NVGC indicator assembly
US5412492A (en) * 1991-11-05 1995-05-02 Magnascreen Corporation Electro-optical lens assembly
WO1993009524A1 (en) * 1991-11-05 1993-05-13 Magnascreen Corporation Liquid crystal lens assembly
US5739882A (en) * 1991-11-18 1998-04-14 Semiconductor Energy Laboratory Co., Ltd. LCD polymerized column spacer formed on a modified substrate, from an acrylic resin, on a surface having hydrophilic and hydrophobic portions, or at regular spacings
US5764316A (en) * 1992-01-30 1998-06-09 Nippon Hoso Kyokai Liquid crystal dimmer plate and lighting system including the same
US5631665A (en) * 1992-11-13 1997-05-20 Nippon Hoso Kyokai Liquid crystal device, driving method thereof, liquid crystal apparatus, and illumination apparatus
US5546208A (en) * 1993-02-19 1996-08-13 Semiconductor Energy Laboratory Co., Ltd. Electrooptical device involving a mixture of liquid crystal, photo curable resins and reaction initiating material for forming resinous columns
US5539545A (en) * 1993-05-18 1996-07-23 Semiconductor Energy Laboratory Co., Ltd. Method of making LCD in which resin columns are cured and the liquid crystal is reoriented
US5676456A (en) * 1995-12-22 1997-10-14 Ncr Corporation Indicator device
US8888304B2 (en) 2012-05-10 2014-11-18 Christopher V. Beckman Optical control techniques
DE102013207416A1 (en) * 2013-04-24 2014-10-30 Siemens Aktiengesellschaft light signal
US20180009453A1 (en) * 2015-01-12 2018-01-11 Siemens Aktiengesellschaft Light Signal
US10525992B2 (en) * 2015-01-12 2020-01-07 Siemens Mobility GmbH Light signal
US11384921B1 (en) * 2021-07-21 2022-07-12 Christopher Neal Bichon Snow shield assembly for use with a traffic signal

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